Volume 16 – Issue 1

In this paper we find an exact value for the game chromatic number of the Cartesian product graph .. W Pn 2 of two graphs, ݊-wheel ܹ௡ and the path graph ܲଶ. This extends a previous work of Sia on the game chromatic number of certain families of Cartesian product graphs. We prove that the game chromatic number of graph .. W P is 5, if n 2 ݊൒3.

In this paper, we study the structure of cyclic and skew cyclic codes over the finite ring D_k = F_q+…+v_kF_q, v^2_i = v_i, v_iv_j = v_jv_i = 0, 1 ≤ i, j≤ k, q =p^m, p is a prime for k≥1 which contains the ring F_q+v_1F_q, v^2_1=v_1. We define a new Gray map fromD_k to F^k+1 _q. The algebraic structures of cyclic codes and duality properties are investigated. A linear code over D_k is represented by means of k+1 q-ary codes. The non trivial automorphism over D_k is given and the skew cyclic codes over D_k are introduced. The algebraic structure of skew cyclic codes and duality properties are investigated. The Gray images of both cyclic and skew cyclic codes over D_k are obtained.

The aim of the present investigation is to establish certain new fractional integral inequalities involving the Appell hypergeometric function considering the extended Chebyshev functional in the case of synchronous functions. In the conclusions numerous special cases as fractional integral inequalities involving Saigo, Erdelyi-Kober,and Riemann-Liouville type fractional integral operators are presented.Further, we also reflect their significance with other related known results due to Purohit, Raina and Belarbi and Dahmani.

We study zero constant mean curvature surface family prescribed by a given curve in Minkowski 3-space. We derive necessary and sufficient condition for zero constant mean curvature surface family prescribed a timelike or spacelike curve. We indicate the condition of a given curve is a geodesic curve or asymptotic curve on zero constant mean curvature surfaces

The aim of this paper is to describe an efficient numerical method for solving general elliptic Monge- Ampere type boundary value problems in two dimensions subject to the Dirichlet boundary conditions. The order of the propose method is quadratic. We have considered model linear and nonlinear problems and solved them to establish the efficiency and accuracy of the propose method.

This study is focused on the structural hardening of ternary Pb-Cd-Mg alloys. The reequilibration of Pb-Cd-Mg alloys was studied by different experimental methods: hardness measurements, optical microscopy and X-ray diffraction. Alloys concerned are : Pb2%Cd1%Mg , Pb2%Cd2%Mg et Pb2%Cd3%Mg. Two structural states were considered: as-cast alloy and rehomogenized alloy. The explored temperatures were 20°C and 80 °C. The structure evolution of Pb -Cd -Mg alloys to the equilibrium state occurs in two stages: the first is characterized by a discontinuous transformation hardening; the second occurs after aging, it is characterized by softening coarse discontinuous precipitation. The addition of magnesium slightly increases the hardness and slow kinetics of the hardening transformation.

Although aluminum is sometimes used alone, we often add to it small amounts of other metals in order to obtain alloys with specific qualities. Some elements of the alloy increase the mechanical resistance or the resistance to corrosion. Other improve: the aptitude to manufacturing; malleability; weldability and; the resistance to high temperatures. Since the range of diverse alloys is very extended, so allows to find that which is most suitable to the envisaged use constraints. Therefore the mechanical properties of aluminum can be modified by the addition of other metals, notably magnesium which considerably contribute to the improvement of mechanical typical features of various alloys and significantly improves the aptitudes to the manufacturing of realised parts. The current study consists of modeling the mechanical properties of the AlCuMg alloys as well as studying the addition effect of magnesium upon the cooling process and upon the evolution of the properties in question

The equation of two body motion was derived with the assumption of mass with spherically symmetric distribution. This equation includes perturbions which represent the deviation from the ideal Kepler’s orbit as a result of external forces effect. These forces can be classified into two types: gravitational forces and non-gravitational forces. In this work gravitational forces includes Earth’s oblateness effect and non-gravitational include Atmospheric drag and Solar radiation pressure. The prediction of orbital lifetime of KufaSat using orbital parameters and engineering specifications as inputs to the Debris Assessment Software (DAS) was done, it has been verified that the orbital lifetime will not be longer than 25 years after completion of mission which is compatible with recommendation of Inter-Agency Space Debris Coordination Committee (IADC).The probability of KufaSat collisions with orbital debris and satellites which operating in the same orbit during orbital lifetime was determined. Apogee/Perigee Altitude History was used to graph apogee and perigee altitudes over KufaSat lifetime .The change in velocity required for maneuvers needed to achieve atmospheric reentry within 25 years was calculated.

The insulation of the electric machines represents a main component which can influence the functional parameters. In the past few decades, it has been recognized that the safety margins in the design were excessive and can greatly increase the cost of the rotor and stator. The aim of this study is to investigate two types of insulating materials in order to develop a new material with better properties and longer life time. In this paper, using Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) technique, was investigated the metal content of studied insulating materials in complementary mode with the Scanning Electron Microscopy – Energy Dispersive X-Ray Spectrometry (SEM-EDS) technique.